Bobbin for weft detecting systems



Patented Apr. 10, 1951 UNITED STATES PATENT OFFICE BOBBIN "FOR WEFT DETECTING ISYSTEMS Richard .G. Turner, Worcester, Mass.,.- assignor to Crompton & Knowles ,-Loom Works, Worcester, Ma' ss., a corporation of Massachusetts Application November 26, 1948, Serial No. 62,204

3 vClaims- 1 This-invention relates to bobbins for the electrical weft detecting systems of looms and it is the general object of :the invention to provide a bobbin having a ferrule capable of conducting electric current but of :such form as to absorb the shock of engagement between thedetector andthebobbin.

:In a common type of electric weft detector two aoppositely charged-detector fingers are slidab1y;mounted on a stationary base and held in position to ;be engaged by the detecting zone :of a weft bobbin. ;So long as sufficient weft for continuedweaving isipresent von the bobbin the detector fingers are :kept insulated from each other, :but when exhaustion Of-Weft approaches an electric conducting ferrule on the bobbin is uncovered and the detector fingers are electrically vide the detecting .zone .of :the bobbin :with,a soft i elastic electric current conducting ferrule which is sufficiently deformable :by the detector fingers toabsorb shoekupon engagement with the fingers and ithereby avoid pinching or breakage of the weft thread. The ferrule-may" preferably be made of :soft electric current conducting pliable rubber'in the form of a tube which may be fitted over the b'ar'relof the=bobbin and be held in position on the bobbin partly at least by its resilience.

Bobbins are generallyprovided with a reserve bunch Qloseto thebutt @for the purpose of enabling the shuttle to lay several picks after indicationof weft exhaustion is given or should be given by the weft detecting system. When metallic ferrules are employed there is a tendency for :this bunch to slipalon-g :therferrule when the shuttle is checked and brought .to-rest abruptly at the end of its flight. It is a further object of the invention to provide a soft elastic weft detecting ferrule which will be sufficiently compressible under the tension of the winding machine which forms the bunch to permit slight deformation of the ferrule by the bunch so that the latter will be held against accidental slippage along the ferrule. In this connection, also, the ferrule has a surface which establishes frictional the :bodyof the .bobbin with a ,recess or the like into which theelastic ferrule can fit, this recess terminating in ashoulder at the end of the ,ferrule remote ,from the bobbin butt. In order to prevent-entry of the weft into the space between the shoulderandthe adjacent end of the ferrule, the latter is preferably formed with a thin fin which extends beyond the shoulder and grips the barrel of the bobbin because .of its resilience in such manner as .to prevent entry of the :weft thread between the .bobbin and the ferrule.

With these and other ,objects in view which will appear as the description proceeds, the invention-resides in the combination and arrangement' of parts hereinafter :described and set forth,

engagement with the last few winds of the boba bin and prevents them from sliding toward the bobbin tip.

It is another object of the invention to provide .In the accompanying :drawings, wherein three forms of the invention are, set forth,

Fig. 1 is a plan :view showing the preferred form of the invention and a type of weft detector with-whichitcanoperate, i Fig. 2 'is a longitudinal section on line 2-2 of Fig. 1,, t V

,Fig. 13 shows the first modification of the invention wherein the ferrule has a tapered weft engaging surface and is of varying thickness so thatitgcanfit the bobbin shown in Fig. 1, and

Fig. 4 shows a second modification of the inventionwherein the ferruleis'tapered but of uniform thickness throughout :its length to fit a nected respectively to wires 1 Sand l-G which lead to :a loom controlling circuit which is not set forth herein. Thedetec'tor may be mounted on a stationary support I! and will ordinarily be in front of the lay of the loom so that it has a detecting operation as the lay moves forwardly. The detector cooperates with a bobbin B which has the customary butt 20 provided with rings 2!, a barrel 22, and a. tip 23.

I The matter thus far described is of usual construction and except as noted hereinafter forms no part of the present invention.

In order that the detector fingers l0 and II may indicate weft exhaustion they must be electrically connected and this is accomplished by means of a ferrule 24 which in the preferred form of the invention is made of soft elastic electric conducting rubber which is generally of cylindrical form, as will be understood from Fig. 2. The bobbin has the body 25 thereof provided with a recess 26 extending from the butt 20 toward the tip 23 of the bobbin and terminating in a shoulder 21. The ferrule 24 is provided with a thin fin 2B which extends beyond the shoulder 21 in a direction toward the bobbin tip.

The ferrule will have an internal diameter slightly less than the diameter of the recess 26 so that when slipped over the barrel of the bobbin and into the recess it will by its own resilience grip the bobbin and tend to hold itself in place in the recess with a fin 28 serving as aguard to prevent entry of weft threads along the shoulder 21. i

As already stated, it is customary to wind a bunch of reserve weft near the bobbin butt, this bunch being for the purpose: of enabling the shuttle to make several flights after exhaustion has occurred and after the time the detector either has or should have indicated weft exhaustion. This bunch is indicated at 29 in Fig. 2, where it will be seen that due to the soft pliable nature of the rubber ferrule 24 the latter is compressed slightly by the bunch, thereby forming a depression 30 in which the bunch is held against accidental slippage toward the bobbin tip. When the detecting surface 3| of ferrule is exposed it will connect the fingers l and II during a detecting operation and cause a change in loom operation.

In the" second form of the invention shown in Fig. 3 the bobbin B can be essentially the same as that of the preferred form, but the ferrule 35 will have a detector surface 36 which is tapered from the butt 20 toward the bobbin tip. In this form of ferrule the inner surface will be essentially cylindrical to fit the recess 26, and the bunch 31 will be of somewhat larger diameter than the bunch 29, but in other respects will be the same as the latter. The ferrule 35 has relatively thick walls 38 adjacent to the butt and thinner walls 39 at the end thereof remote from the butt. A fin 40 integral with ferrule 35 is similar in form and purpose to fin 28 in the preferred form of the invention.

In the second modification shown in Fig. 4 the bobbin B will be somewhat different from the bobbins of the first two forms in that its body 43 is formed with a conical zone 44 forminga recess 45 tapered in a direction from the butt 46 toward the opposite end of the bobbin. The ferrule 4! is'of uniform thickness but is generally tapered to conform to the tapered zone 44 of the body of the bobbin. Ferrule 41 has a detector surface 48 similar to surfaces 3| and 36.

In all forms of the invention the ferrule is sufficiently elastic to permit fitting over the barrel of the bobbin and then snapping into the receiving recess in the bobbin body to be held by its own resilience in proper position for cooperation with the detector D. The ferrules are all made of the same material, that is, a soft elastic rubber capable of conducting electric current, and all serve as a shock absorber to prevent abrasion or injury of fine wefts by the detector fingers I 0 and I I. Also, in all forms the ferrule will yield slightly at the site of the reserve bunch to hold the latter against slipping toward the tip end of the bobbin. In the first two forms of the invention the fins 28 and 40 fit the bobbin barrel closely due to their resilience and prevent the weft from getting into positions between the barrel and the body of the bobbin. In the second form of the invention shown in Fig. 4 the fins are omitted, but can be used if desired.

Having thus describedthe invention it will be seen that changes and modifications of the foregoing specific disclosures may be made without departing from the spirit and scope of the invention.

What is claimed as new is:

1. In a weft bobbin for use with the electric weft detector of a loom, a bobbin body having an annular recess therein adjacent to the butt, the body having a weft carrying barrel, said recess terminating in a shoulder at the end thereof remote from the bobbin butt and adjacent to said barrel, a soft elastic electric current conducting ferrule in said recess, and a fin integral with the ferrule projecting over the shoulder and engaging the barrel to prevent the weft from moving to a position between the ferrule and shoulder.

2.In a weft bobbin for use with the electric weft detector of a loom, a bobbin body having an annular recess therein formed with a shoulder, a soft elastic electric current conducting ferrule in said recess, and a fin integral with the ferrule gripping the bobbin barrel due to the resilience thereof and extending over said shoulder.

3. In a weft bobbin for use with the electric weft detector of a loom, a bobbin body formed with a butt and a tip, and a ferrule of soft elastic electric current conducting rubber held to the bobbin body and having a detecting surface tapering from the butt toward the top, and a fin to prevent a weft thread from moving to a po-' sition between the ferrule and body of the bobbin.

RICHARD G. TURNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

